[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20200203090619.GL1778@kadam>
Date: Mon, 3 Feb 2020 12:06:19 +0300
From: Dan Carpenter <dan.carpenter@...cle.com>
To: Daniel Vetter <daniel@...ll.ch>
Cc: syzbot <syzbot+0dc4444774d419e916c8@...kaller.appspotmail.com>,
Dave Airlie <airlied@...ux.ie>,
Alex Deucher <alexander.deucher@....com>,
amd-gfx list <amd-gfx@...ts.freedesktop.org>,
"Wilson, Chris" <chris@...is-wilson.co.uk>,
Christian König <christian.koenig@....com>,
David Miller <davem@...emloft.net>,
dri-devel <dri-devel@...ts.freedesktop.org>,
Emil Velikov <emil.velikov@...labora.com>,
"Anholt, Eric" <eric@...olt.net>,
"moderated list:DMA BUFFER SHARING FRAMEWORK"
<linaro-mm-sig@...ts.linaro.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
"open list:DMA BUFFER SHARING FRAMEWORK"
<linux-media@...r.kernel.org>, netdev <netdev@...r.kernel.org>,
Rob Clark <robdclark@...omium.org>,
Sean Paul <seanpaul@...omium.org>,
Sumit Semwal <sumit.semwal@...aro.org>,
syzkaller-bugs <syzkaller-bugs@...glegroups.com>
Subject: Re: KASAN: use-after-free Read in vgem_gem_dumb_create
On Sun, Feb 02, 2020 at 02:19:18PM +0100, Daniel Vetter wrote:
> On Fri, Jan 31, 2020 at 11:28 PM syzbot
> <syzbot+0dc4444774d419e916c8@...kaller.appspotmail.com> wrote:
> >
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: 39bed42d Merge tag 'for-linus-hmm' of git://git.kernel.org..
> > git tree: upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=179465bee00000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=2646535f8818ae25
> > dashboard link: https://syzkaller.appspot.com/bug?extid=0dc4444774d419e916c8
> > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16251279e00000
> >
> > The bug was bisected to:
> >
> > commit 7611750784664db46d0db95631e322aeb263dde7
> > Author: Alex Deucher <alexander.deucher@....com>
> > Date: Wed Jun 21 16:31:41 2017 +0000
> >
> > drm/amdgpu: use kernel is_power_of_2 rather than local version
> >
> > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11628df1e00000
> > final crash: https://syzkaller.appspot.com/x/report.txt?x=13628df1e00000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=15628df1e00000
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+0dc4444774d419e916c8@...kaller.appspotmail.com
> > Fixes: 761175078466 ("drm/amdgpu: use kernel is_power_of_2 rather than local version")
>
> Aside: This bisect line is complete nonsense ... I'm kinda at the
> point where I'm assuming that syzbot bisect results are garbage, which
> is maybe not what we want. I guess much stricter filtering for noise
> is needed, dunno.
> -Danile
With race conditions the git bisect is often nonsense.
regards,
dan carpenter
Powered by blists - more mailing lists